Concurrent Papillary Carcinoma of Thyroglossal Duct Cyst and Thyroid Isthmus, Beyond the Sistrunk Procedure

Introduction/Background: Papillary carcinoma (PC) originating from the thyroglossal cyst is a rare entity. It is even more uncommon to have concurrent thyroglossal duct cyst PC and papillary thyroid carcinomas (PTC). The surgical approach for such patients would involve a combination of a Sistrunk’s procedure and total thyroidectomy. We describe management of a patient found to have multi focal PC originating from a thyroglossal duct cyst and thyroid isthmus with extensive cervical lymph node metastasis. Clinical Case: 30-year-old male presented to PCP with palpable bilateral cervical adenopathy most prominent in the right supraclavicular region. Neck ultrasound confirmed multiple metastatic appearing nodes (largest 4cm) in the central, right and left lateral cervical compartments as well as a hypoechoic, TI-RADS category 5 right thyroid isthmus nodule. FNA of the cervical nodes confirmed metastatic PTC. Neck CT in addition to extensive cervical adenopathy revealed a 2 cm solid mass inferior to the central hyoid bone with infiltrative borders and calcifications suspicious for a primary tumor. Patient underwent total thyroidectomy with central compartment lymph node dissection, excision of thyroglossal cyst and bilateral modified radical neck dissections. Histopathology report revealed a 2.4 cm thyroglossal duct tumor and a 1.1 cm tumor in the thyroid isthmus, confirming two separate tumors both being classical variants of papillary thyroid carcinoma, with no lympho-vascular invasion and 8/53 positive lymph nodes. BRAF V600E mutation was positive. On follow up, the patient is doing well and has deferred adjuvant radioactive iodine treatment for 6 months for personal reasons. Clinical Lesson/ Conclusion: PC of the thyroglossal cyst with synchronous isthmic PTC merits total thyroidectomy and central compartment dissection in addition to the Sistrunk’s procedure, as the likelihood of local metastasis is high. Presence of BRAF V600E mutation has been identified as a predictor of more aggressive behavior in isolated PC of the thyroglossal duct cyst, suggesting a need for more than a Sistrunk’s procedure in such patients. Our patient, who presented with local lymph node metastasis supports this conclusion. Determining BRAF mutation status preoperatively may be a helpful strategy in planning the extent of surgery. Keywords Thyroglossal duct cyst, Papillary thyroid carcinoma, BRAF mutation

Isolated thyroid carcinoma in an ectopic thyroid tissue

Ectopic thyroid tissue (ETT) is a rare developmental abnormality due to aberrant embryogenesis of the thyroid gland. Although rare (<1%), papillary thyroid carcinoma (PTC) is the most common malignant transformation seen. A 34-year-old man presented with neck nodal swelling, on preoperative evaluation, was found to have PT) in ETT with the normal thyroid gland and nodal metastasis. The patient underwent surgery for PTC along with Sistrunk’s procedure and the histopathology revealed ectopic thyroid carcinoma with a normal thyroid and lymph nodal metastasis. Although a rare entity, the possibility of an ectopic thyroid carcinoma should be considered in differentiated cancers with neck nodes in the setting of a normal thyroid gland. Clinical suspicion and radiological imaging would help improve the preoperative diagnosis which in turn alters the management and thereby providing a better outcome to the patient.

Incidence and outcome of thyroglossal duct cyst

<p class="abstract"><strong>Background:</strong> Thyroglossal duct cyst (TGDC) is the cyst in the cervical midline that arises from the embryonic remnant of the thryroglossal duct. It is most common congenital abnormality in the head and neck region which may present at any age particularly occur in children. The definitive treatment is surgical excision of the cyst and tract.</p><p class="abstract"><strong>Methods:</strong> It is a cohort retrospective study of 26 cases in the Department of Otorhinolaryngology and Head-Neck surgery, Comilla Medical College Hospital, Bangladesh from 01 July 2016 to 31 June 2019. </p><p class="abstract"><strong>Results:</strong> Incidence of TGDC was 0.02% out of total outdoor patient and 0.94% in total indoor routine operation. All patient was operated by Sistrunk’s procedure and recurrent 2 (7.69%) cases were operated by modified or extended Sistrunk’s procedure without complications afterwards. Of them female was 14 (53.85%), male was 12 (46.15%), children were 22 (84.61%), adult were 4 (15.35%). Infrahyoid was 21 (80.76%), surahyoid was 5 (19.24%). The patient presented as painful abscess were 10 (38.46%) and fistula were 3(11.51%), painless cyst was 8 (30.77%) and fistula were 5 (19.24%).</p><p class="abstract"><strong>Conclusions:</strong> TGDC is common congenital anomaly. It has a various type of presenting feature. Sistrunk’s procedure is gold standard surgical treatment procedure. But recurrence cases need modified or extended Sistrunk’s procedure to minimize the postoperative complication and manage the patient’s hope and requirements.</p>

A mixed thyroglossal cyst

The case is described of a boy who presented at age six months with symptoms and signs of a thyroglossal cyst, which seemed to be confirmed by ultrasound findings. The cyst slowly increased in size, and eventually the patient underwent Sistrunk’s procedure at age four years. Histology showed that the cyst was in fact a mixed thyroglossal and dermoid cyst. This casts doubt on the doctrine that thyroglossal cysts and dermoid cysts are anatomically and histologically separate entities, and strengthens the view that these cysts should be more appropriately named ’thyroglossal abnormalities’.

Management of thyroglossal tract disease after failed Sistrunk’s procedure

Sistrunk’s procedure for thyroglossal duct remnants has a very high success rate, there remains the occasional patient, however, that will have recurrent disease despite a competently performed operation. Applied anatomy and embryology proffer a solution to this problem. Extending the Sistrunk operation, with an anterior wide local excision remaining within normal tissue, enables removal of the entire thyroglossal tract remnant.A retrospective case note review was conducted to study our experience using this extended procedure to treat patients with thyroglossal tract disease that had recurred after a previous Sistrunk’s operation.Six patients aged from five to 33 years were included in the study. There was one recurrence and the complication rate was comparable to the standard operation.It was concluded that a wide local excision is a valuable extension of the Sistrunk operation for the management of recurrent disease.